Hardness Scale Converter (HRC/HB/HV/HRB/Mohs) implementation

Binding contract

This record describes what an executable surface must bind and validate. It does not claim that a public calculator, package, or production route is deployed.

Record owner

Guth Instruments

Lifecycle

verified-clean

Evidence ID

t7-014

Effect

Computation or source lookup only

Input and validation requirements

The principal breaks are out-of-domain hardness values that must be rejected rather than interpolated, plus ambiguity when a bare hardness number or tensile-strength unit is supplied. A lookup engine that silently extrapolates HRC 0 or HRC 1,000,000, or assumes an unlabeled scale, can return materially misleading results.

Required corrections

No binding erratum is attached to this unique-name record. Implementers must still preserve the declared units, domain, and failure behavior.

Inspectable interface fixture

The sample below is evidence for interface and validation tests, not a production implementation.

{
  "inputs": {
    "hardness_value": 30,
    "input_scale": "HRC",
    "material_class": "steel"
  },
  "expected_outputs": {
    "HRC": 30,
    "HB": 286,
    "HV": 302,
    "approx_tensile_strength_MPa": 1010
  },
  "reference_data": {
    "table_type": "Rockwell C to Brinell/Vickers/tensile strength, steel",
    "HRC_30": {
      "HB": 286,
      "HV": 302,
      "approx_tensile_strength_MPa": 1010
    },
    "source_convention": "ASTM E140 steel conversion table convention, widely tabulated standard value"
  },
  "working": "Input is exactly the HRC 30 row. Therefore HRC = 30, HB = 286, and HV = 302 with no interpolation. The steel-table tensile estimate is 1010 MPa."
}

Other records

Sources and evidence

These pointers bind the page to evidence. They do not grant authority or collapse verification into deployment.

• VERIFIED_LEDGER.json
• evidence-tranche7/tranche7-results.json